This invention is a device to be used for determining whether a beverage is of the artificially sweetened xe2x80x9cdietxe2x80x9d variety or the sugar sweetened variety. This is useful for beverages, such as carbonated soft drinks, which are sold in both varieties, the two being almost identical in taste and appearance. Many people, such as diabetics or calorie-conscious dieters, could benefit from a simple, reliable means of differentiating between the two varieties.
This invention uses the index of refraction of the beverage to determine whether the beverage contains sugar. As the concentration of sugar in a beverage is increased, the index of retraction of the beverage increases as well. Because artificial sweeteners are only used in minute quantities in diet soft drinks, the refractive index of diet drinks is essentially the same as that of pure water. A typical sugar sweetened soft drink, on the other hand, contains enough sugar to make its refractive index considerably higher than that of its artificially sweetened counterpart.
The sugar sweetened versions of most soft drinks contain about 12% sugar by weight as they come from the bottle and may vary as low as 6% sugar after dilution by melted ice.
The device consists of a probe which is dipped into the beverage to be tested, together with electronic circuitry which determines the type of beverage being tested. The device turns on an indicator light to display the result of the test. The invention has advantages over devices such as that described in U.S. Pat. No. 5,859,696, xe2x80x9cRefractometer for distinguishing sugar-sweetened beverages from artificially-sweetened onesxe2x80x9d, which require enough ambient light for the user to be able to see light passing through the liquid. This invention is easier to use because the user only needs to dip the probe in the beverage and press a button to perform a test. The test is also more discreet because the user does not need to raise the device to his eye. This invention has an advantage over chemical test strips which can only be used once and which have a limited shelf life. The device is only intended to indicate whether a beverage is of the diet or sugar-sweetened variety, rather than producing a high accuracy measurement of refractive index. Thus it can be simpler, more compact and more economical than devices which produce high accuracy measurements.
This device could be useful to those people who wish to avoid sugar because of diabetes, dental problems or weight control concerns. People with phenylketonuria (PKU) must avoid aspartame, a common artificial sweetener. Some people experience nervous system problems when they drink beverages containing aspartame and may wish to avoid diet soft drinks. Many people are wary of any possible long term health effects of consuming artificial sweeteners and want to avoid them to reduce their possible risk of cancer or other illnesses.